This invention relates to a surfing boom of light weight which is excellent in mechanical strength.
In the wind-surfing, to steer a surfboard, a boom is used, which is formed by connecting both ends of two curved poles by means of joint in the form of a loop. For the formation of such booms, there has been used hitherto a curved pipe of aluminum alloy but such metallic booms are not satisfied in their light weight and strength. In the utility model laid-open No. 59-13396, a boom is proposed in which a pipe of aluminum alloy, in which the inside and outside of its curved portions are reinforced with a carbon fiber-reinforced plastics is used. Since the pipe surface of this boom is reinforced with a carbon fiber-reinforced plastics, it is lighter and improved in the hold maintenance by hand compared with the above-mentioned pipe of aluminum alloy. However, such boom is not yet satisfied in the light weight and the steering property because of using a pipe of aluminum alloy.